1. Field of Invention
This invention relates to a capacitive discharge type ignition apparatus using an ignition transformer; and more particularly, to an improvement thereof wherein efficiency is greatly increased.
2. Description of the Prior Art
FIG. 5 shows a block diagram of a prior ignition apparatus, wherein AC power is applied to a primary winding of a step-up transformer T.sub.r1 and AC voltage is obtained from a secondary winding thereof. The obtained AC voltage is half-wave rectified with a diode D.sub.1, which then charges a tank condenser C.sub.1. When the voltage level stored in tank condenser C.sub.1 reaches the discharging voltage level of a spark gap G.sub.1, a trigger current i.sub.t flows through a primary winding of an ignition transformer T.sub.r2, which is connected to a trigger condenser C.sub.2 so that a high voltage is induced in a secondary winding of ignition transformer T.sub.r2.
The other end of the secondary winding of ignition transformer T.sub.r2 is corrected to an igniter plug P. When the isolation gap between the electrodes of plug P is broken down by the high voltage, a high power ignition spark occurs and a spark current i.sub.s flows through the secondary winding of ignition transformer T.sub.r2.
However, the prior ignition apparatus has many deficiencies. For example, since the impedance of the secondary winding of the ignition transformer is comparatively large, power loss is high, and therefore, efficiency is degraded considerably.